001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.actions.mapmode;
003
004import static org.openstreetmap.josm.gui.help.HelpUtil.ht;
005import static org.openstreetmap.josm.tools.I18n.marktr;
006import static org.openstreetmap.josm.tools.I18n.tr;
007
008import java.awt.BasicStroke;
009import java.awt.Color;
010import java.awt.Cursor;
011import java.awt.Graphics2D;
012import java.awt.Point;
013import java.awt.Rectangle;
014import java.awt.Stroke;
015import java.awt.event.ActionEvent;
016import java.awt.event.KeyEvent;
017import java.awt.event.MouseEvent;
018import java.awt.geom.AffineTransform;
019import java.awt.geom.GeneralPath;
020import java.awt.geom.Line2D;
021import java.awt.geom.NoninvertibleTransformException;
022import java.awt.geom.Point2D;
023import java.util.ArrayList;
024import java.util.Collection;
025import java.util.LinkedList;
026import java.util.List;
027import javax.swing.JCheckBoxMenuItem;
028import javax.swing.JMenuItem;
029
030import org.openstreetmap.josm.Main;
031import org.openstreetmap.josm.actions.JosmAction;
032import org.openstreetmap.josm.actions.MergeNodesAction;
033import org.openstreetmap.josm.command.AddCommand;
034import org.openstreetmap.josm.command.ChangeCommand;
035import org.openstreetmap.josm.command.Command;
036import org.openstreetmap.josm.command.MoveCommand;
037import org.openstreetmap.josm.command.SequenceCommand;
038import org.openstreetmap.josm.data.Bounds;
039import org.openstreetmap.josm.data.coor.EastNorth;
040import org.openstreetmap.josm.data.osm.Node;
041import org.openstreetmap.josm.data.osm.OsmPrimitive;
042import org.openstreetmap.josm.data.osm.Way;
043import org.openstreetmap.josm.data.osm.WaySegment;
044import org.openstreetmap.josm.data.osm.visitor.paint.PaintColors;
045import org.openstreetmap.josm.gui.MainMenu;
046import org.openstreetmap.josm.gui.MapFrame;
047import org.openstreetmap.josm.gui.MapView;
048import org.openstreetmap.josm.gui.layer.Layer;
049import org.openstreetmap.josm.gui.layer.MapViewPaintable;
050import org.openstreetmap.josm.gui.layer.OsmDataLayer;
051import org.openstreetmap.josm.gui.util.KeyPressReleaseListener;
052import org.openstreetmap.josm.gui.util.GuiHelper;
053import org.openstreetmap.josm.gui.util.ModifierListener;
054import org.openstreetmap.josm.tools.Geometry;
055import org.openstreetmap.josm.tools.ImageProvider;
056import org.openstreetmap.josm.tools.Shortcut;
057
058/**
059 * Makes a rectangle from a line, or modifies a rectangle.
060 */
061public class ExtrudeAction extends MapMode implements MapViewPaintable, KeyPressReleaseListener, ModifierListener {
062
063    enum Mode { extrude, translate, select, create_new, translate_node }
064
065    private Mode mode = Mode.select;
066
067    /**
068     * If {@code true}, when extruding create new node(s) even if segments are parallel.
069     */
070    private boolean alwaysCreateNodes = false;
071    private boolean nodeDragWithoutCtrl;
072
073    private long mouseDownTime = 0;
074    private WaySegment selectedSegment = null;
075    private Node selectedNode = null;
076    private Color mainColor;
077    private Stroke mainStroke;
078
079    /** settings value whether shared nodes should be ignored or not */
080    private boolean ignoreSharedNodes;
081
082    private boolean keepSegmentDirection;
083
084    /**
085     * drawing settings for helper lines
086     */
087    private Color helperColor;
088    private Stroke helperStrokeDash;
089    private Stroke helperStrokeRA;
090
091    private Stroke oldLineStroke;
092    private double symbolSize;
093    /**
094     * Possible directions to move to.
095     */
096    private List<ReferenceSegment> possibleMoveDirections;
097
098
099    /**
100     * Collection of nodes that is moved
101     */
102    private ArrayList<Node> movingNodeList;
103
104    /**
105     * The direction that is currently active.
106     */
107    private ReferenceSegment activeMoveDirection;
108
109    /**
110     * The position of the mouse cursor when the drag action was initiated.
111     */
112    private Point initialMousePos;
113    /**
114     * The time which needs to pass between click and release before something
115     * counts as a move, in milliseconds
116     */
117    private int initialMoveDelay = 200;
118    /**
119     * The minimal shift of mouse (in pixels) befire something counts as move
120     */
121    private int initialMoveThreshold = 1;
122
123    /**
124     * The initial EastNorths of node1 and node2
125     */
126    private EastNorth initialN1en;
127    private EastNorth initialN2en;
128    /**
129     * The new EastNorths of node1 and node2
130     */
131    private EastNorth newN1en;
132    private EastNorth newN2en;
133
134    /**
135     * the command that performed last move.
136     */
137    private MoveCommand moveCommand;
138    /**
139     *  The command used for dual alignment movement.
140     *  Needs to be separate, due to two nodes moving in different directions.
141     */
142    private MoveCommand moveCommand2;
143
144    /** The cursor for the 'create_new' mode. */
145    private final Cursor cursorCreateNew;
146
147    /** The cursor for the 'translate' mode. */
148    private final Cursor cursorTranslate;
149
150    /** The cursor for the 'alwaysCreateNodes' submode. */
151    private final Cursor cursorCreateNodes;
152
153    private static class ReferenceSegment {
154        public final EastNorth en;
155        public final EastNorth p1;
156        public final EastNorth p2;
157        public final boolean perpendicular;
158
159        public ReferenceSegment(EastNorth en, EastNorth p1, EastNorth p2, boolean perpendicular) {
160            this.en = en;
161            this.p1 = p1;
162            this.p2 = p2;
163            this.perpendicular = perpendicular;
164        }
165
166        @Override
167        public String toString() {
168            return "ReferenceSegment[en=" + en + ", p1=" + p1 + ", p2=" + p2 + ", perp=" + perpendicular + "]";
169        }
170    }
171
172    // Dual alignment mode stuff
173    /** {@code true}, if dual alignment mode is enabled. User wants following extrude to be dual aligned. */
174    private boolean dualAlignEnabled;
175    /** {@code true}, if dual alignment is active. User is dragging the mouse, required conditions are met. Treat {@link #mode} (extrude/translate/create_new) as dual aligned. */
176    private boolean dualAlignActive;
177    /** Dual alignment reference segments */
178    private ReferenceSegment dualAlignSegment1, dualAlignSegment2;
179    /** {@code true}, if new segment was collapsed */
180    private boolean dualAlignSegmentCollapsed = false;
181    // Dual alignment UI stuff
182    private final DualAlignChangeAction dualAlignChangeAction;
183    private final JCheckBoxMenuItem dualAlignCheckboxMenuItem;
184    private final Shortcut dualAlignShortcut;
185    private boolean useRepeatedShortcut;
186    private boolean ignoreNextKeyRelease;
187
188    private class DualAlignChangeAction extends JosmAction {
189        public DualAlignChangeAction() {
190            super(tr("Dual alignment"), "mapmode/extrude/dualalign",
191                    tr("Switch dual alignment mode while extruding"), null, false);
192            putValue("help", ht("/Action/Extrude#DualAlign"));
193        }
194
195        @Override
196        public void actionPerformed(ActionEvent e) {
197            toggleDualAlign();
198        }
199    }
200
201    /**
202     * Creates a new ExtrudeAction
203     * @param mapFrame The MapFrame this action belongs to.
204     */
205    public ExtrudeAction(MapFrame mapFrame) {
206        super(tr("Extrude"), "extrude/extrude", tr("Create areas"),
207                Shortcut.registerShortcut("mapmode:extrude", tr("Mode: {0}", tr("Extrude")), KeyEvent.VK_X, Shortcut.DIRECT),
208                mapFrame,
209                ImageProvider.getCursor("normal", "rectangle"));
210        putValue("help", ht("/Action/Extrude"));
211        cursorCreateNew = ImageProvider.getCursor("normal", "rectangle_plus");
212        cursorTranslate = ImageProvider.getCursor("normal", "rectangle_move");
213        cursorCreateNodes = ImageProvider.getCursor("normal", "rectangle_plussmall");
214
215        dualAlignEnabled = false;
216        dualAlignChangeAction = new DualAlignChangeAction();
217        dualAlignCheckboxMenuItem = addDualAlignMenuItem();
218        dualAlignCheckboxMenuItem.getAction().setEnabled(false);
219        dualAlignCheckboxMenuItem.setState(dualAlignEnabled);
220        dualAlignShortcut = Shortcut.registerShortcut("mapmode:extrudedualalign",
221                tr("Mode: {0}", tr("Extrude Dual alignment")), KeyEvent.CHAR_UNDEFINED, Shortcut.NONE);
222        readPreferences(); // to show prefernces in table before entering the mode
223    }
224
225    @Override
226    public void destroy() {
227        super.destroy();
228        dualAlignChangeAction.destroy();
229    }
230
231    private JCheckBoxMenuItem addDualAlignMenuItem() {
232        int n = Main.main.menu.editMenu.getItemCount();
233        for (int i = n-1; i>0; i--) {
234            JMenuItem item = Main.main.menu.editMenu.getItem(i);
235            if (item != null && item.getAction() != null && item.getAction() instanceof DualAlignChangeAction) {
236                Main.main.menu.editMenu.remove(i);
237            }
238        }
239        return MainMenu.addWithCheckbox(Main.main.menu.editMenu, dualAlignChangeAction, MainMenu.WINDOW_MENU_GROUP.VOLATILE);
240    }
241
242    // -------------------------------------------------------------------------
243    // Mode methods
244    // -------------------------------------------------------------------------
245
246    @Override
247    public String getModeHelpText() {
248        StringBuilder rv;
249        if (mode == Mode.select) {
250            rv = new StringBuilder(tr("Drag a way segment to make a rectangle. Ctrl-drag to move a segment along its normal, " +
251                "Alt-drag to create a new rectangle, double click to add a new node."));
252            if (dualAlignEnabled) {
253                rv.append(" ").append(tr("Dual alignment active."));
254                if (dualAlignSegmentCollapsed)
255                    rv.append(" ").append(tr("Segment collapsed due to its direction reversing."));
256            }
257        } else {
258            if (mode == Mode.translate)
259                rv = new StringBuilder(tr("Move a segment along its normal, then release the mouse button."));
260            else if (mode == Mode.translate_node)
261                rv = new StringBuilder(tr("Move the node along one of the segments, then release the mouse button."));
262            else if (mode == Mode.extrude)
263                rv = new StringBuilder(tr("Draw a rectangle of the desired size, then release the mouse button."));
264            else if (mode == Mode.create_new)
265                rv = new StringBuilder(tr("Draw a rectangle of the desired size, then release the mouse button."));
266            else {
267                Main.warn("Extrude: unknown mode " + mode);
268                rv = new StringBuilder();
269            }
270            if (dualAlignActive) {
271                rv.append(" ").append(tr("Dual alignment active."));
272                if (dualAlignSegmentCollapsed) {
273                    rv.append(" ").append(tr("Segment collapsed due to its direction reversing."));
274                }
275            }
276        }
277        return rv.toString();
278    }
279
280    @Override
281    public boolean layerIsSupported(Layer l) {
282        return l instanceof OsmDataLayer;
283    }
284
285    @Override
286    public void enterMode() {
287        super.enterMode();
288        Main.map.mapView.addMouseListener(this);
289        Main.map.mapView.addMouseMotionListener(this);
290        readPreferences();
291        ignoreNextKeyRelease = true;
292        Main.map.keyDetector.addKeyListener(this);
293        Main.map.keyDetector.addModifierListener(this);
294    }
295
296    private void readPreferences() {
297        initialMoveDelay = Main.pref.getInteger("edit.initial-move-delay",200);
298        initialMoveThreshold = Main.pref.getInteger("extrude.initial-move-threshold", 1);
299        mainColor = Main.pref.getColor(marktr("Extrude: main line"), null);
300        if (mainColor == null) mainColor = PaintColors.SELECTED.get();
301        helperColor = Main.pref.getColor(marktr("Extrude: helper line"), Color.ORANGE);
302        helperStrokeDash = GuiHelper.getCustomizedStroke(Main.pref.get("extrude.stroke.helper-line", "1 4"));
303        helperStrokeRA = new BasicStroke(1);
304        symbolSize = Main.pref.getDouble("extrude.angle-symbol-radius", 8);
305        nodeDragWithoutCtrl = Main.pref.getBoolean("extrude.drag-nodes-without-ctrl", false);
306        oldLineStroke = GuiHelper.getCustomizedStroke(Main.pref.get("extrude.ctrl.stroke.old-line", "1"));
307        mainStroke = GuiHelper.getCustomizedStroke(Main.pref.get("extrude.stroke.main", "3"));
308
309        ignoreSharedNodes = Main.pref.getBoolean("extrude.ignore-shared-nodes", true);
310        dualAlignCheckboxMenuItem.getAction().setEnabled(true);
311        useRepeatedShortcut = Main.pref.getBoolean("extrude.dualalign.toggleOnRepeatedX", true);
312        keepSegmentDirection = Main.pref.getBoolean("extrude.dualalign.keep-segment-direction", true);
313    }
314
315    @Override
316    public void exitMode() {
317        Main.map.mapView.removeMouseListener(this);
318        Main.map.mapView.removeMouseMotionListener(this);
319        Main.map.mapView.removeTemporaryLayer(this);
320        dualAlignCheckboxMenuItem.getAction().setEnabled(false);
321        Main.map.keyDetector.removeKeyListener(this);
322        Main.map.keyDetector.removeModifierListener(this);
323        super.exitMode();
324    }
325
326    // -------------------------------------------------------------------------
327    // Event handlers
328    // -------------------------------------------------------------------------
329
330    /**
331     * This method is called to indicate different modes via cursor when the Alt/Ctrl/Shift modifier is pressed,
332     */
333    @Override
334    public void modifiersChanged(int modifiers) {
335        if (!Main.isDisplayingMapView() || !Main.map.mapView.isActiveLayerDrawable())
336            return;
337        updateKeyModifiers(modifiers);
338        if (mode == Mode.select) {
339            Main.map.mapView.setNewCursor(ctrl ? cursorTranslate : alt ? cursorCreateNew : shift ? cursorCreateNodes : cursor, this);
340        }
341    };
342
343    @Override
344    public void doKeyPressed(KeyEvent e) {
345    }
346
347    @Override
348    public void doKeyReleased(KeyEvent e) {
349        if (!dualAlignShortcut.isEvent(e) && !(useRepeatedShortcut && getShortcut().isEvent(e)))
350             return;
351        if (ignoreNextKeyRelease) {
352            ignoreNextKeyRelease = false;
353        } else {
354            toggleDualAlign();
355        }
356    }
357    /**
358     * Toggles dual alignment mode.
359     */
360    private void toggleDualAlign() {
361        dualAlignEnabled = !dualAlignEnabled;
362        dualAlignCheckboxMenuItem.setState(dualAlignEnabled);
363        updateStatusLine();
364    }
365
366    /**
367     * If the left mouse button is pressed over a segment or a node, switches
368     * to appropriate {@link #mode}, depending on Ctrl/Alt/Shift modifiers and
369     * {@link #dualAlignEnabled}.
370     * @param e
371     */
372    @Override
373    public void mousePressed(MouseEvent e) {
374        if(!Main.map.mapView.isActiveLayerVisible())
375            return;
376        if (!(Boolean)this.getValue("active"))
377            return;
378        if (e.getButton() != MouseEvent.BUTTON1)
379            return;
380
381        requestFocusInMapView();
382        updateKeyModifiers(e);
383
384        selectedNode = Main.map.mapView.getNearestNode(e.getPoint(), OsmPrimitive.isSelectablePredicate);
385        selectedSegment = Main.map.mapView.getNearestWaySegment(e.getPoint(), OsmPrimitive.isSelectablePredicate);
386
387        // If nothing gets caught, stay in select mode
388        if (selectedSegment == null && selectedNode == null) return;
389
390        if (selectedNode != null) {
391            if (ctrl || nodeDragWithoutCtrl) {
392                movingNodeList = new ArrayList<>();
393                movingNodeList.add(selectedNode);
394                calculatePossibleDirectionsByNode();
395                if (possibleMoveDirections.isEmpty()) {
396                    // if no directions fould, do not enter dragging mode
397                    return;
398                }
399                mode = Mode.translate_node;
400                dualAlignActive = false;
401            }
402        } else {
403            // Otherwise switch to another mode
404            if (dualAlignEnabled && checkDualAlignConditions()) {
405                dualAlignActive = true;
406                calculatePossibleDirectionsForDualAlign();
407                dualAlignSegmentCollapsed = false;
408            } else {
409                dualAlignActive = false;
410                calculatePossibleDirectionsBySegment();
411            }
412            if (ctrl) {
413                mode = Mode.translate;
414                movingNodeList = new ArrayList<>();
415                movingNodeList.add(selectedSegment.getFirstNode());
416                movingNodeList.add(selectedSegment.getSecondNode());
417            } else if (alt) {
418                mode = Mode.create_new;
419                // create a new segment and then select and extrude the new segment
420                getCurrentDataSet().setSelected(selectedSegment.way);
421                alwaysCreateNodes = true;
422            } else {
423                mode = Mode.extrude;
424                getCurrentDataSet().setSelected(selectedSegment.way);
425                alwaysCreateNodes = shift;
426            }
427        }
428
429        // Signifies that nothing has happened yet
430        newN1en = null;
431        newN2en = null;
432        moveCommand = null;
433        moveCommand2 = null;
434
435        Main.map.mapView.addTemporaryLayer(this);
436
437        updateStatusLine();
438        Main.map.mapView.repaint();
439
440        // Make note of time pressed
441        mouseDownTime = System.currentTimeMillis();
442
443        // Make note of mouse position
444        initialMousePos = e.getPoint();
445   }
446
447    /**
448     * Performs action depending on what {@link #mode} we're in.
449     * @param e
450     */
451    @Override
452    public void mouseDragged(MouseEvent e) {
453        if(!Main.map.mapView.isActiveLayerVisible())
454            return;
455
456        // do not count anything as a drag if it lasts less than 100 milliseconds.
457        if (System.currentTimeMillis() - mouseDownTime < initialMoveDelay)
458            return;
459
460        if (mode == Mode.select) {
461            // Just sit tight and wait for mouse to be released.
462        } else {
463            //move, create new and extrude mode - move the selected segment
464
465            EastNorth mouseEn = Main.map.mapView.getEastNorth(e.getPoint().x, e.getPoint().y);
466            EastNorth bestMovement = calculateBestMovementAndNewNodes(mouseEn);
467
468            Main.map.mapView.setNewCursor(Cursor.MOVE_CURSOR, this);
469
470            if (dualAlignActive) {
471                if (mode == Mode.extrude || mode == Mode.create_new) {
472                    // nothing here
473                } else if (mode == Mode.translate) {
474                    EastNorth movement1 = initialN1en.sub(newN1en);
475                    EastNorth movement2 = initialN2en.sub(newN2en);
476                    // move nodes to new position
477                    if (moveCommand == null || moveCommand2 == null) {
478                        // make a new move commands
479                        moveCommand = new MoveCommand(movingNodeList.get(0), movement1.getX(), movement1.getY());
480                        moveCommand2 = new MoveCommand(movingNodeList.get(1), movement2.getX(), movement2.getY());
481                        Command c = new SequenceCommand(tr("Extrude Way"), moveCommand, moveCommand2);
482                        Main.main.undoRedo.add(c);
483                    } else {
484                        // reuse existing move commands
485                        moveCommand.moveAgainTo(movement1.getX(), movement1.getY());
486                        moveCommand2.moveAgainTo(movement2.getX(), movement2.getY());
487                    }
488                }
489            } else {
490                if (mode == Mode.extrude || mode == Mode.create_new) {
491                    //nothing here
492                } else if (mode == Mode.translate_node || mode == Mode.translate) {
493                    //move nodes to new position
494                    if (moveCommand == null) {
495                        //make a new move command
496                        moveCommand = new MoveCommand(new ArrayList<OsmPrimitive>(movingNodeList), bestMovement);
497                        Main.main.undoRedo.add(moveCommand);
498                    } else {
499                        //reuse existing move command
500                        moveCommand.moveAgainTo(bestMovement.getX(), bestMovement.getY());
501                    }
502                }
503            }
504
505            Main.map.mapView.repaint();
506        }
507    }
508
509    /**
510     * Does anything that needs to be done, then switches back to select mode.
511     * @param e
512     */
513    @Override
514    public void mouseReleased(MouseEvent e) {
515
516        if(!Main.map.mapView.isActiveLayerVisible())
517            return;
518
519        if (mode == Mode.select) {
520            // Nothing to be done
521        } else {
522            if (mode == Mode.create_new) {
523                if (e.getPoint().distance(initialMousePos) > initialMoveThreshold && newN1en != null) {
524                    createNewRectangle();
525                }
526            } else if (mode == Mode.extrude) {
527                if( e.getClickCount() == 2 && e.getPoint().equals(initialMousePos) ) {
528                    // double click adds a new node
529                    addNewNode(e);
530                }
531                else if (e.getPoint().distance(initialMousePos) > initialMoveThreshold && newN1en != null && selectedSegment != null) {
532                    // main extrusion commands
533                    performExtrusion();
534                }
535            } else if (mode == Mode.translate || mode == Mode.translate_node) {
536                //Commit translate
537                //the move command is already committed in mouseDragged
538                joinNodesIfCollapsed(movingNodeList);
539            }
540
541            updateKeyModifiers(e);
542            // Switch back into select mode
543            Main.map.mapView.setNewCursor(ctrl ? cursorTranslate : alt ? cursorCreateNew : shift ? cursorCreateNodes : cursor, this);
544            Main.map.mapView.removeTemporaryLayer(this);
545            selectedSegment = null;
546            moveCommand = null;
547            mode = Mode.select;
548            dualAlignSegmentCollapsed = false;
549            updateStatusLine();
550            Main.map.mapView.repaint();
551        }
552    }
553
554    // -------------------------------------------------------------------------
555    // Custom methods
556    // -------------------------------------------------------------------------
557
558    /**
559     * Inserts node into nearby segment.
560     * @param e current mouse point
561     */
562    private void addNewNode(MouseEvent e) {
563        // Should maybe do the same as in DrawAction and fetch all nearby segments?
564        WaySegment ws = Main.map.mapView.getNearestWaySegment(e.getPoint(), OsmPrimitive.isSelectablePredicate);
565        if (ws != null) {
566            Node n = new Node(Main.map.mapView.getLatLon(e.getX(), e.getY()));
567            EastNorth A = ws.getFirstNode().getEastNorth();
568            EastNorth B = ws.getSecondNode().getEastNorth();
569            n.setEastNorth(Geometry.closestPointToSegment(A, B, n.getEastNorth()));
570            Way wnew = new Way(ws.way);
571            wnew.addNode(ws.lowerIndex+1, n);
572            SequenceCommand cmds = new SequenceCommand(tr("Add a new node to an existing way"),
573                    new AddCommand(n), new ChangeCommand(ws.way, wnew));
574            Main.main.undoRedo.add(cmds);
575        }
576    }
577
578    /**
579     * Creates a new way that shares segment with selected way.
580     */
581    private void createNewRectangle() {
582        if (selectedSegment == null) return;
583        // crete a new rectangle
584        Collection<Command> cmds = new LinkedList<>();
585        Node third = new Node(newN2en);
586        Node fourth = new Node(newN1en);
587        Way wnew = new Way();
588        wnew.addNode(selectedSegment.getFirstNode());
589        wnew.addNode(selectedSegment.getSecondNode());
590        wnew.addNode(third);
591        if (!dualAlignSegmentCollapsed) {
592            // rectangle can degrade to triangle for dual alignment after collapsing
593            wnew.addNode(fourth);
594        }
595        // ... and close the way
596        wnew.addNode(selectedSegment.getFirstNode());
597        // undo support
598        cmds.add(new AddCommand(third));
599        if (!dualAlignSegmentCollapsed) {
600            cmds.add(new AddCommand(fourth));
601        }
602        cmds.add(new AddCommand(wnew));
603        Command c = new SequenceCommand(tr("Extrude Way"), cmds);
604        Main.main.undoRedo.add(c);
605        getCurrentDataSet().setSelected(wnew);
606    }
607
608    /**
609     * Does actual extrusion of {@link #selectedSegment}.
610     * Uses {@link #initialN1en}, {@link #initialN2en} saved in calculatePossibleDirections* call
611     * Uses {@link #newN1en}, {@link #newN2en} calculated by {@link #calculateBestMovementAndNewNodes}
612     */
613    private void performExtrusion() {
614        // create extrusion
615        Collection<Command> cmds = new LinkedList<>();
616        Way wnew = new Way(selectedSegment.way);
617        boolean wayWasModified = false;
618        boolean wayWasSingleSegment = wnew.getNodesCount() == 2;
619        int insertionPoint = selectedSegment.lowerIndex + 1;
620
621        //find if the new points overlap existing segments (in case of 90 degree angles)
622        Node prevNode = getPreviousNode(selectedSegment.lowerIndex);
623        boolean nodeOverlapsSegment = prevNode != null && Geometry.segmentsParallel(initialN1en, prevNode.getEastNorth(), initialN1en, newN1en);
624        // segmentAngleZero marks subset of nodeOverlapsSegment. nodeOverlapsSegment is true if angle between segments is 0 or PI, segmentAngleZero only if angle is 0
625        boolean segmentAngleZero = prevNode != null && Math.abs(Geometry.getCornerAngle(prevNode.getEastNorth(), initialN1en, newN1en)) < 1e-5;
626        boolean hasOtherWays = hasNodeOtherWays(selectedSegment.getFirstNode(), selectedSegment.way);
627        ArrayList<Node> changedNodes = new ArrayList<>();
628        if (nodeOverlapsSegment && !alwaysCreateNodes && !hasOtherWays) {
629            //move existing node
630            Node n1Old = selectedSegment.getFirstNode();
631            cmds.add(new MoveCommand(n1Old, Main.getProjection().eastNorth2latlon(newN1en)));
632            changedNodes.add(n1Old);
633        } else if (ignoreSharedNodes && segmentAngleZero && !alwaysCreateNodes && hasOtherWays) {
634            // replace shared node with new one
635            Node n1Old = selectedSegment.getFirstNode();
636            Node n1New = new Node(Main.getProjection().eastNorth2latlon(newN1en));
637            wnew.addNode(insertionPoint, n1New);
638            wnew.removeNode(n1Old);
639            wayWasModified = true;
640            cmds.add(new AddCommand(n1New));
641            changedNodes.add(n1New);
642        } else {
643            //introduce new node
644            Node n1New = new Node(Main.getProjection().eastNorth2latlon(newN1en));
645            wnew.addNode(insertionPoint, n1New);
646            wayWasModified = true;
647            insertionPoint ++;
648            cmds.add(new AddCommand(n1New));
649            changedNodes.add(n1New);
650        }
651
652        //find if the new points overlap existing segments (in case of 90 degree angles)
653        Node nextNode = getNextNode(selectedSegment.lowerIndex + 1);
654        nodeOverlapsSegment = nextNode != null && Geometry.segmentsParallel(initialN2en, nextNode.getEastNorth(), initialN2en, newN2en);
655        segmentAngleZero = nextNode != null && Math.abs(Geometry.getCornerAngle(nextNode.getEastNorth(), initialN2en, newN2en)) < 1e-5;
656        hasOtherWays = hasNodeOtherWays(selectedSegment.getSecondNode(), selectedSegment.way);
657
658        if (nodeOverlapsSegment && !alwaysCreateNodes && !hasOtherWays) {
659            //move existing node
660            Node n2Old = selectedSegment.getSecondNode();
661            cmds.add(new MoveCommand(n2Old, Main.getProjection().eastNorth2latlon(newN2en)));
662            changedNodes.add(n2Old);
663        } else if (ignoreSharedNodes && segmentAngleZero && !alwaysCreateNodes && hasOtherWays) {
664            // replace shared node with new one
665            Node n2Old = selectedSegment.getSecondNode();
666            Node n2New = new Node(Main.getProjection().eastNorth2latlon(newN2en));
667            wnew.addNode(insertionPoint, n2New);
668            wnew.removeNode(n2Old);
669            wayWasModified = true;
670            cmds.add(new AddCommand(n2New));
671            changedNodes.add(n2New);
672        } else {
673            //introduce new node
674            Node n2New = new Node(Main.getProjection().eastNorth2latlon(newN2en));
675            wnew.addNode(insertionPoint, n2New);
676            wayWasModified = true;
677            insertionPoint ++;
678            cmds.add(new AddCommand(n2New));
679            changedNodes.add(n2New);
680        }
681
682        //the way was a single segment, close the way
683        if (wayWasSingleSegment) {
684            wnew.addNode(selectedSegment.getFirstNode());
685            wayWasModified = true;
686        }
687        if (wayWasModified) {
688            // we only need to change the way if its node list was really modified
689            cmds.add(new ChangeCommand(selectedSegment.way, wnew));
690        }
691        Command c = new SequenceCommand(tr("Extrude Way"), cmds);
692        Main.main.undoRedo.add(c);
693        joinNodesIfCollapsed(changedNodes);
694    }
695
696    private void joinNodesIfCollapsed(List<Node> changedNodes) {
697        if (!dualAlignActive || newN1en == null || newN2en == null) return;
698        if (newN1en.distance(newN2en) > 1e-6) return;
699        // If the dual alignment moved two nodes to the same point, merge them
700        Node targetNode = MergeNodesAction.selectTargetNode(changedNodes);
701        Node locNode = MergeNodesAction.selectTargetLocationNode(changedNodes);
702        Command mergeCmd = MergeNodesAction.mergeNodes(Main.main.getEditLayer(), changedNodes, targetNode, locNode);
703        if (mergeCmd!=null) {
704            Main.main.undoRedo.add(mergeCmd);
705        } else {
706            // undo extruding command itself
707            Main.main.undoRedo.undo();
708        }
709    }
710
711    /**
712     * This method tests if {@code node} has other ways apart from the given one.
713     * @param node
714     * @param myWay
715     * @return {@code true} if {@code node} belongs only to {@code myWay}, false if there are more ways.
716     */
717    private static boolean hasNodeOtherWays(Node node, Way myWay) {
718        for (OsmPrimitive p : node.getReferrers()) {
719            if (p instanceof Way && p.isUsable() && p != myWay)
720                return true;
721        }
722        return false;
723    }
724
725    /**
726     * Determines best movement from {@link #initialMousePos} to current mouse position,
727     * choosing one of the directions from {@link #possibleMoveDirections}.
728     * @param mouseEn current mouse position
729     * @return movement vector
730     */
731    private EastNorth calculateBestMovement(EastNorth mouseEn) {
732
733        EastNorth initialMouseEn = Main.map.mapView.getEastNorth(initialMousePos.x, initialMousePos.y);
734        EastNorth mouseMovement = initialMouseEn.sub(mouseEn);
735
736        double bestDistance = Double.POSITIVE_INFINITY;
737        EastNorth bestMovement = null;
738        activeMoveDirection = null;
739
740        //find the best movement direction and vector
741        for (ReferenceSegment direction : possibleMoveDirections) {
742            EastNorth movement = calculateSegmentOffset(initialN1en, initialN2en, direction.en, mouseEn);
743            if (movement == null) {
744                //if direction parallel to segment.
745                continue;
746            }
747
748            double distanceFromMouseMovement = movement.distance(mouseMovement);
749            if (bestDistance > distanceFromMouseMovement) {
750                bestDistance = distanceFromMouseMovement;
751                activeMoveDirection = direction;
752                bestMovement = movement;
753            }
754        }
755        return bestMovement;
756
757
758    }
759
760    /***
761     * This method calculates offset amount by which to move the given segment
762     * perpendicularly for it to be in line with mouse position.
763     * @param segmentP1 segment's first point
764     * @param segmentP2 segment's second point
765     * @param moveDirection direction of movement
766     * @param targetPos mouse position
767     * @return offset amount of P1 and P2.
768     */
769    private static EastNorth calculateSegmentOffset(EastNorth segmentP1, EastNorth segmentP2, EastNorth moveDirection,
770            EastNorth targetPos) {
771        EastNorth intersectionPoint;
772        if (segmentP1.distanceSq(segmentP2)>1e-7) {
773            intersectionPoint = Geometry.getLineLineIntersection(segmentP1, segmentP2, targetPos, targetPos.add(moveDirection));
774        } else {
775            intersectionPoint = Geometry.closestPointToLine(targetPos, targetPos.add(moveDirection), segmentP1);
776        }
777
778        if (intersectionPoint == null)
779            return null;
780        else
781            //return distance form base to target position
782            return intersectionPoint.sub(targetPos);
783    }
784
785    /**
786     * Gathers possible move directions - perpendicular to the selected segment
787     * and parallel to neighboring segments.
788     */
789    private void calculatePossibleDirectionsBySegment() {
790        // remember initial positions for segment nodes.
791        initialN1en = selectedSegment.getFirstNode().getEastNorth();
792        initialN2en = selectedSegment.getSecondNode().getEastNorth();
793
794        //add direction perpendicular to the selected segment
795        possibleMoveDirections = new ArrayList<>();
796        possibleMoveDirections.add(new ReferenceSegment(new EastNorth(
797                initialN1en.getY() - initialN2en.getY(),
798                initialN2en.getX() - initialN1en.getX()
799                ), initialN1en, initialN2en, true));
800
801
802        //add directions parallel to neighbor segments
803        Node prevNode = getPreviousNode(selectedSegment.lowerIndex);
804        if (prevNode != null) {
805            EastNorth en = prevNode.getEastNorth();
806            possibleMoveDirections.add(new ReferenceSegment(new EastNorth(
807                    initialN1en.getX() - en.getX(),
808                    initialN1en.getY() - en.getY()
809                    ), initialN1en, en, false));
810        }
811
812        Node nextNode = getNextNode(selectedSegment.lowerIndex + 1);
813        if (nextNode != null) {
814            EastNorth en = nextNode.getEastNorth();
815            possibleMoveDirections.add(new ReferenceSegment(new EastNorth(
816                    initialN2en.getX() - en.getX(),
817                    initialN2en.getY() - en.getY()
818                    ), initialN2en,  en, false));
819        }
820    }
821
822    /**
823     * Gathers possible move directions - along all adjacent segments.
824     */
825    private void calculatePossibleDirectionsByNode() {
826        // remember initial positions for segment nodes.
827        initialN1en = selectedNode.getEastNorth();
828        initialN2en = initialN1en;
829        possibleMoveDirections = new ArrayList<>();
830        for (OsmPrimitive p: selectedNode.getReferrers()) {
831            if (p instanceof Way  && p.isUsable()) {
832                for (Node neighbor: ((Way) p).getNeighbours(selectedNode)) {
833                    EastNorth en = neighbor.getEastNorth();
834                    possibleMoveDirections.add(new ReferenceSegment(new EastNorth(
835                        initialN1en.getX() - en.getX(),
836                        initialN1en.getY() - en.getY()
837                    ), initialN1en, en, false));
838                }
839            }
840        }
841    }
842
843    /**
844     * Checks dual alignment conditions:
845     *  1. selected segment has both neighboring segments,
846     *  2. selected segment is not parallel with neighboring segments.
847     * @return {@code true} if dual alignment conditions are satisfied
848     */
849    private boolean checkDualAlignConditions() {
850        Node prevNode = getPreviousNode(selectedSegment.lowerIndex);
851        Node nextNode = getNextNode(selectedSegment.lowerIndex + 1);
852        if (prevNode == null || nextNode == null) {
853            return false;
854        }
855
856        EastNorth n1en = selectedSegment.getFirstNode().getEastNorth();
857        EastNorth n2en = selectedSegment.getSecondNode().getEastNorth();
858        if (n1en.distance(prevNode.getEastNorth())<1e-4 ||
859            n2en.distance(nextNode.getEastNorth())<1e-4 ) {
860            return false;
861        }
862
863        boolean prevSegmentParallel = Geometry.segmentsParallel(n1en, prevNode.getEastNorth(), n1en, n2en);
864        boolean nextSegmentParallel = Geometry.segmentsParallel(n2en, nextNode.getEastNorth(), n1en, n2en);
865        if (prevSegmentParallel || nextSegmentParallel) {
866            return false;
867        }
868
869        return true;
870    }
871
872    /**
873     * Gathers possible move directions - perpendicular to the selected segment only.
874     * Neighboring segments go to {@link #dualAlignSegment1} and {@link #dualAlignSegment2}.
875     */
876    private void calculatePossibleDirectionsForDualAlign() {
877        // remember initial positions for segment nodes.
878        initialN1en = selectedSegment.getFirstNode().getEastNorth();
879        initialN2en = selectedSegment.getSecondNode().getEastNorth();
880
881        // add direction perpendicular to the selected segment
882        possibleMoveDirections = new ArrayList<ReferenceSegment>();
883        possibleMoveDirections.add(new ReferenceSegment(new EastNorth(
884                initialN1en.getY() - initialN2en.getY(),
885                initialN2en.getX() - initialN1en.getX()
886                ), initialN1en, initialN2en, true));
887
888        // set neighboring segments
889        Node prevNode = getPreviousNode(selectedSegment.lowerIndex);
890        EastNorth prevNodeEn = prevNode.getEastNorth();
891        dualAlignSegment1 = new ReferenceSegment(new EastNorth(
892            initialN1en.getX() - prevNodeEn.getX(),
893            initialN1en.getY() - prevNodeEn.getY()
894            ), initialN1en, prevNodeEn, false);
895
896        Node nextNode = getNextNode(selectedSegment.lowerIndex + 1);
897        EastNorth nextNodeEn = nextNode.getEastNorth();
898        dualAlignSegment2 = new ReferenceSegment(new EastNorth(
899            initialN2en.getX() - nextNodeEn.getX(),
900            initialN2en.getY() - nextNodeEn.getY()
901            ), initialN2en,  nextNodeEn, false);
902    }
903
904    /**
905     * Calculate newN1en, newN2en best suitable for given mouse coordinates
906     * For dual align, calculates positions of new nodes, aligning them to neighboring segments.
907     * Elsewhere, just adds the vetor returned by calculateBestMovement to {@link #initialN1en},  {@link #initialN2en}.
908     * @return best movement vector
909     */
910    private EastNorth calculateBestMovementAndNewNodes(EastNorth mouseEn) {
911        EastNorth bestMovement = calculateBestMovement(mouseEn);
912        EastNorth n1movedEn = initialN1en.add(bestMovement), n2movedEn;
913
914        // find out the movement distance, in metres
915        double distance = Main.getProjection().eastNorth2latlon(initialN1en).greatCircleDistance(Main.getProjection().eastNorth2latlon(n1movedEn));
916        Main.map.statusLine.setDist(distance);
917        updateStatusLine();
918
919        if (dualAlignActive) {
920            // new positions of selected segment's nodes, without applying dual alignment
921            n1movedEn = initialN1en.add(bestMovement);
922            n2movedEn = initialN2en.add(bestMovement);
923
924            // calculate intersections of parallel shifted segment and the adjacent lines
925            newN1en = Geometry.getLineLineIntersection(n1movedEn, n2movedEn, dualAlignSegment1.p1, dualAlignSegment1.p2);
926            newN2en = Geometry.getLineLineIntersection(n1movedEn, n2movedEn, dualAlignSegment2.p1, dualAlignSegment2.p2);
927            if (newN1en == null || newN2en == null) return bestMovement;
928            if (keepSegmentDirection && isOppositeDirection(newN1en, newN2en, initialN1en, initialN2en)) {
929                EastNorth collapsedSegmentPosition = Geometry.getLineLineIntersection(dualAlignSegment1.p1, dualAlignSegment1.p2, dualAlignSegment2.p1, dualAlignSegment2.p2);
930                newN1en = collapsedSegmentPosition;
931                newN2en = collapsedSegmentPosition;
932                dualAlignSegmentCollapsed = true;
933            } else {
934                dualAlignSegmentCollapsed = false;
935            }
936        } else {
937            newN1en = n1movedEn;
938            newN2en = initialN2en.add(bestMovement);
939        }
940        return bestMovement;
941    }
942
943    /**
944     * Gets a node index from selected way before given index.
945     * @param index  index of current node
946     * @return index of previous node or <code>-1</code> if there are no nodes there.
947     */
948    private int getPreviousNodeIndex(int index) {
949        if (index > 0)
950            return index - 1;
951        else if (selectedSegment.way.isClosed())
952            return selectedSegment.way.getNodesCount() - 2;
953        else
954            return -1;
955    }
956
957    /**
958     * Gets a node from selected way before given index.
959     * @param index  index of current node
960     * @return previous node or <code>null</code> if there are no nodes there.
961     */
962    private Node getPreviousNode(int index) {
963        int indexPrev = getPreviousNodeIndex(index);
964        if (indexPrev >= 0)
965            return selectedSegment.way.getNode(indexPrev);
966        else
967            return null;
968    }
969
970
971    /**
972     * Gets a node index from selected way after given index.
973     * @param index index of current node
974     * @return index of next node or <code>-1</code> if there are no nodes there.
975     */
976    private int getNextNodeIndex(int index) {
977        int count = selectedSegment.way.getNodesCount();
978        if (index <  count - 1)
979            return index + 1;
980        else if (selectedSegment.way.isClosed())
981            return 1;
982        else
983            return -1;
984    }
985
986    /**
987     * Gets a node from selected way after given index.
988     * @param index index of current node
989     * @return next node or <code>null</code> if there are no nodes there.
990     */
991    private Node getNextNode(int index) {
992        int indexNext = getNextNodeIndex(index);
993        if (indexNext >= 0)
994            return selectedSegment.way.getNode(indexNext);
995        else
996            return null;
997    }
998
999    // -------------------------------------------------------------------------
1000    // paint methods
1001    // -------------------------------------------------------------------------
1002
1003    @Override
1004    public void paint(Graphics2D g, MapView mv, Bounds box) {
1005        Graphics2D g2 = g;
1006        if (mode == Mode.select) {
1007            // Nothing to do
1008        } else {
1009            if (newN1en != null) {
1010
1011                Point p1 = mv.getPoint(initialN1en);
1012                Point p2 = mv.getPoint(initialN2en);
1013                Point p3 = mv.getPoint(newN1en);
1014                Point p4 = mv.getPoint(newN2en);
1015
1016                Point2D normalUnitVector = getNormalUniVector();
1017
1018                if (mode == Mode.extrude || mode == Mode.create_new) {
1019                    g2.setColor(mainColor);
1020                    g2.setStroke(mainStroke);
1021                    // Draw rectangle around new area.
1022                    GeneralPath b = new GeneralPath();
1023                    b.moveTo(p1.x, p1.y); b.lineTo(p3.x, p3.y);
1024                    b.lineTo(p4.x, p4.y); b.lineTo(p2.x, p2.y);
1025                    b.lineTo(p1.x, p1.y);
1026                    g2.draw(b);
1027
1028                    if (dualAlignActive) {
1029                        // Draw reference ways
1030                        drawReferenceSegment(g2, mv, dualAlignSegment1);
1031                        drawReferenceSegment(g2, mv, dualAlignSegment2);
1032                    } else if (activeMoveDirection != null) {
1033                        // Draw reference way
1034                        drawReferenceSegment(g2, mv, activeMoveDirection);
1035
1036                        // Draw right angle marker on first node position, only when moving at right angle
1037                        if (activeMoveDirection.perpendicular) {
1038                            // mirror RightAngle marker, so it is inside the extrude
1039                            double headingRefWS = activeMoveDirection.p1.heading(activeMoveDirection.p2);
1040                            double headingMoveDir = Math.atan2(normalUnitVector.getY(), normalUnitVector.getX());
1041                            double headingDiff = headingRefWS - headingMoveDir;
1042                            if (headingDiff < 0) headingDiff += 2 * Math.PI;
1043                            boolean mirrorRA = Math.abs(headingDiff - Math.PI) > 1e-5;
1044                            Point pr1 = mv.getPoint(activeMoveDirection.p1);
1045                            drawAngleSymbol(g2, pr1, normalUnitVector, mirrorRA);
1046                        }
1047                    }
1048                } else if (mode == Mode.translate || mode == Mode.translate_node) {
1049                    g2.setColor(mainColor);
1050                    if (p1.distance(p2) < 3) {
1051                        g2.setStroke(mainStroke);
1052                        g2.drawOval((int)(p1.x-symbolSize/2), (int)(p1.y-symbolSize/2),
1053                                (int)(symbolSize), (int)(symbolSize));
1054                    } else {
1055                        Line2D oldline = new Line2D.Double(p1, p2);
1056                        g2.setStroke(oldLineStroke);
1057                        g2.draw(oldline);
1058                    }
1059
1060                    if (dualAlignActive) {
1061                        // Draw reference ways
1062                        drawReferenceSegment(g2, mv, dualAlignSegment1);
1063                        drawReferenceSegment(g2, mv, dualAlignSegment2);
1064                    } else if (activeMoveDirection != null) {
1065
1066                        g2.setColor(helperColor);
1067                        g2.setStroke(helperStrokeDash);
1068                        // Draw a guideline along the normal.
1069                        Line2D normline;
1070                        Point2D centerpoint = new Point2D.Double((p1.getX()+p2.getX())*0.5, (p1.getY()+p2.getY())*0.5);
1071                        normline = createSemiInfiniteLine(centerpoint, normalUnitVector, g2);
1072                        g2.draw(normline);
1073                        // Draw right angle marker on initial position, only when moving at right angle
1074                        if (activeMoveDirection.perpendicular) {
1075                            // EastNorth units per pixel
1076                            g2.setStroke(helperStrokeRA);
1077                            g2.setColor(mainColor);
1078                            drawAngleSymbol(g2, centerpoint, normalUnitVector, false);
1079                        }
1080                    }
1081                }
1082            }
1083            g2.setStroke(helperStrokeRA); // restore default stroke to prevent starnge occasional drawings
1084        }
1085    }
1086
1087    private Point2D getNormalUniVector() {
1088        double fac = 1.0 / activeMoveDirection.en.length();
1089        // mult by factor to get unit vector.
1090        Point2D normalUnitVector = new Point2D.Double(activeMoveDirection.en.getX() * fac, activeMoveDirection.en.getY() * fac);
1091
1092        // Check to see if our new N1 is in a positive direction with respect to the normalUnitVector.
1093        // Even if the x component is zero, we should still be able to discern using +0.0 and -0.0
1094        if (newN1en != null && ((newN1en.getX() > initialN1en.getX()) != (normalUnitVector.getX() > -0.0))) {
1095            // If not, use a sign-flipped version of the normalUnitVector.
1096            normalUnitVector = new Point2D.Double(-normalUnitVector.getX(), -normalUnitVector.getY());
1097        }
1098
1099        //HACK: swap Y, because the target pixels are top down, but EastNorth is bottom-up.
1100        //This is normally done by MapView.getPoint, but it does not work on vectors.
1101        normalUnitVector.setLocation(normalUnitVector.getX(), -normalUnitVector.getY());
1102        return normalUnitVector;
1103    }
1104
1105    /**
1106     * Returns true if from1-to1 and from2-to2 vertors directions are opposite
1107     */
1108    private boolean isOppositeDirection(EastNorth from1, EastNorth to1, EastNorth from2, EastNorth to2) {
1109        return (from1.getX()-to1.getX())*(from2.getX()-to2.getX())
1110              +(from1.getY()-to1.getY())*(from2.getY()-to2.getY()) < 0;
1111    }
1112
1113    /**
1114     * Draws right angle symbol at specified position.
1115     * @param g2 the Graphics2D object used to draw on
1116     * @param center center point of angle
1117     * @param normal vector of normal
1118     * @param mirror {@code true} if symbol should be mirrored by the normal
1119     */
1120    private void drawAngleSymbol(Graphics2D g2, Point2D center, Point2D normal, boolean mirror) {
1121        // EastNorth units per pixel
1122        double factor = 1.0/g2.getTransform().getScaleX();
1123        double raoffsetx = symbolSize*factor*normal.getX();
1124        double raoffsety = symbolSize*factor*normal.getY();
1125
1126        double cx = center.getX(), cy = center.getY();
1127        double k = (mirror ? -1 : 1);
1128        Point2D ra1 = new Point2D.Double(cx + raoffsetx, cy + raoffsety);
1129        Point2D ra3 = new Point2D.Double(cx - raoffsety*k, cy + raoffsetx*k);
1130        Point2D ra2 = new Point2D.Double(ra1.getX() - raoffsety*k, ra1.getY() + raoffsetx*k);
1131
1132        GeneralPath ra = new GeneralPath();
1133        ra.moveTo((float)ra1.getX(), (float)ra1.getY());
1134        ra.lineTo((float)ra2.getX(), (float)ra2.getY());
1135        ra.lineTo((float)ra3.getX(), (float)ra3.getY());
1136        g2.setStroke(helperStrokeRA);
1137        g2.draw(ra);
1138    }
1139
1140    /**
1141     * Draws given reference segment.
1142     * @param g2 the Graphics2D object used to draw on
1143     * @param mv
1144     * @param seg the reference segment
1145     */
1146    private void drawReferenceSegment(Graphics2D g2, MapView mv, ReferenceSegment seg)
1147    {
1148        Point p1 = mv.getPoint(seg.p1);
1149        Point p2 = mv.getPoint(seg.p2);
1150        GeneralPath b = new GeneralPath();
1151        b.moveTo(p1.x, p1.y);
1152        b.lineTo(p2.x, p2.y);
1153        g2.setColor(helperColor);
1154        g2.setStroke(helperStrokeDash);
1155        g2.draw(b);
1156    }
1157
1158    /**
1159     * Creates a new Line that extends off the edge of the viewport in one direction
1160     * @param start The start point of the line
1161     * @param unitvector A unit vector denoting the direction of the line
1162     * @param g the Graphics2D object  it will be used on
1163     * @return created line
1164     */
1165    private static Line2D createSemiInfiniteLine(Point2D start, Point2D unitvector, Graphics2D g) {
1166        Rectangle bounds = g.getDeviceConfiguration().getBounds();
1167        try {
1168            AffineTransform invtrans = g.getTransform().createInverse();
1169            Point2D widthpoint = invtrans.deltaTransform(new Point2D.Double(bounds.width,0), null);
1170            Point2D heightpoint = invtrans.deltaTransform(new Point2D.Double(0,bounds.height), null);
1171
1172            // Here we should end up with a gross overestimate of the maximum viewport diagonal in what
1173            // Graphics2D calls 'user space'. Essentially a manhattan distance of manhattan distances.
1174            // This can be used as a safe length of line to generate which will always go off-viewport.
1175            double linelength = Math.abs(widthpoint.getX()) + Math.abs(widthpoint.getY()) + Math.abs(heightpoint.getX()) + Math.abs(heightpoint.getY());
1176
1177            return new Line2D.Double(start, new Point2D.Double(start.getX() + (unitvector.getX() * linelength) , start.getY() + (unitvector.getY() * linelength)));
1178        }
1179        catch (NoninvertibleTransformException e) {
1180            return new Line2D.Double(start, new Point2D.Double(start.getX() + (unitvector.getX() * 10) , start.getY() + (unitvector.getY() * 10)));
1181        }
1182    }
1183}